CELL-MEDIATED IMMUNITY

1
CELL-MEDIATED IMMUNITY

• Antigen presentation
• Formation of viral proteins by macrophage
• Formation of antigen-MHC complex

• TH cell activation
• Binding of TH cell to antigen-MHC complex
• Release of cytokines from macrophage
• Activation of TH cell to release cytokines

• TC cell activation
• Activation of virgin and memory TC cells by
  cytokines
• Promotion of mitosis and differentiation of TC
  cells

• Cellular destruction
• Binding of effector TC cell to infected body
  cell
• Induction of cell lysis by release of perforins.

2
HUMORAL IMMUNITY

• Antigen presentation
• Formation of viral proteins by macrophage
• Formation of antigen-MHC complex

• TH cell activation
• Binding of TH cell to antigen-MHC complex
• Release of cytokines from macrophage
• Activation of TH cell to release cytokines

• B cell activation
• Activation of virgin and memory B cells by
  cytokines
• Promotion of mitosis and differentiation of B
  cells

• Antibodies production
• Release of circulating antibodies into the
  bloodstream from the plasma cells

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ROLE OF CYTOKINES IN ACQUIRED IMMUNITY
TNF-b IFN-g
Interleukin 2
Interleukin 1
Cytokine Site of Release Stimulus Effects
Interleukin-1 Macrophage Antigen-MHC complex Release of IL-2 release from TH cells
Interleukin-2 TH cell Antigenic stimulation IL-1 signals Induction of IL-2 receptor production Activation of virgin memory TC and B cells
TNF-b Activated TC cell Activated TC cells Cytotoxicity of target cells
IFN-g Activated TC cell Antigen-MHC complex Activation of macrophages Increased expression of MHC
TNF-b Tumor Necrosis Factor b IFN-g Interferon g
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STRUCTURE OF IMMUNOGLOBULIN
Glycoprotein molecules produced by plasma cells
in response to an antigen
Light Chain
VL
CL
VH
CH1
CHO
Hinge
CH2
CH3
Constant Region
Variable Region
Heavy Chain
CHO
Domains
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STRUCTURES FUNCTIONS OF IMMUNOGLOBULINS
Papain
Pepsin
Fc Peptides
Fab
Fc
F(ab) 2
Antigenic binding
Effector functions
Antigenic binding No effector functions
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IMMUNOGLOBULIN DIVERSITY
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IMMUNOGLOBULINS IN ACTION
Opsonization
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IMMUNOGLOBULINS IN ACTION
Exotoxin Neutralization
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IMMUNOGLOBULINS IN ACTION
Viral Neutralization
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IMMUNOGLOBULINS IN ACTION
Complement fixation
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IMMUNOGLOBULINS IN ACTION
Cytotoxicity
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IMMUNOGLOBULINS IN ACTION
Agglutination
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IMMUNOGLOBULINS IN ACTION
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PRIMARY AND SECONDARY IMMUNE RESPONSES
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ACTIVE VERSUS PASSIVE IMMUNITY
Acquired Immunity
Artificially Acquired
Naturally Acquired